Optical Coatings on Telescopes

Summary: This is why some telescopes cost substantially more than others.

For most people, seeing the planets will require little more than a telescope and a clear evening. However, serious star gazers will want to consider an upgrade to telescopes that feature lenses treated by optical coating systems. These lenses have several advantages over the standard store-bought varieties, but they aren’t always easy for the newcomer to recognize. If you’re wondering why some telescopes are vastly different in price, this may help you understand.

Coating Types

Before we dive into coating types, we need to first make note of the method in which the lens is coated. Cheaper methods, like the dip and bake, may lower the cost to you but the quality suffers greatly. The coatings don’t last as long as an ebeam coating would. Within a year or two you’ll literally wipe away the coating.

Aluminum and titanium oxide, as well as magnesium fluoride, represent the most common substance used. High quality lenses are “fully coated,” which means that the coating has been applied to both sides. This is different from “multi-coated” lenses, which may also carry a high price tag. The multi-coat name comes from the multiple layers of chemicals applied to the lens in order to alter properties like light transmission.

Buying Your Telescope

In addition to any coatings applied to the lens of the telescope, you might want some additional upgrades. A tripod mounted telescope, for instance, are easy to set up and provide stability. You can also purchase telescopes with recording capabilities, so you can capture video footage for time lapse editing later.

Tip of the Day

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